Lipo Noob

[teamorsum96]

Hi, i am thinking about changing my LRP shark to lipo's now but i dont have a clue what im looking for, i am running Tekin Mini Rage brushless esc and 6.9kv motor.

I have been looking at getting a few of these, Overlander 2s lipo 2200mah 7.4 25c

but what i dont understand is what is the other connector on it for (not the battery connectors) and do i need to plug that in to the charger same time i am charging the pack up.

any help is great for this lipo noob

cheers